The present invention generally relates to gear hinges and more specifically to gear hinge devices employing a bearing having an end edge which is not entirely perpendicular to the longitudinal axis of the hinge.
Because doors attached to a door frame with traditional pin-type hinges have their weight concentrated at a few relatively small areas where the hinges are located, continuous gear hinges are often preferable. Gear hinges usually extend the entire length of a hinge jamb or door, and thus distribute the weight of the door over a much larger area. For this reason, gear hinges are often installed on doors which see heavy use, such as those found in bathroom stalls.
A gear hinge typically has two opposing hinge members, each having a longitudinal leaf and a gear segment for meshing with an opposing gear segment, a hinge cap or clamp for holding the gear segments together so that one leaf can rotate relative to the other leaf while the gear segments remain meshed, and one or more bearing blocks for preventing one hinge member from shifting longitudinally relative to another hinge member. A gear hinge for a typical door will have several bearing blocks fitted into cutouts formed in the leaves and gear segments, and these bearing blocks, which are usually molded from plastic, carry essentially the entire weight of the door. As the hinge opens and closes, the ends of the cutouts in the gear segments slide over the end edges of the plastic bearing blocks, which can cause unwanted friction and wear over time. Plus, such doors with common gear hinges do not open or close automatically, without additional hardware.
Bathroom stalls subject to the Americans with Disabilities Act (ADA) must have doors that are self-closing. To achieve such a self-closing door, some doors use springs. However, these springs are subject to failure. Moreover, for non-ADA bathroom stall doors, there is a demand for a door that returns to a specific, non-closed position. This position is typically 15°-20° with respect to the closed position, leaving enough of an opening for a person to easily determine whether the stall is occupied or not.
One embodiment of the present invention is a gear hinge assembly including a pair of mating hinge members and one or more bearing blocks. Each bearing block has one or more non-perpendicular—with respect to the longitudinal axis—end edge surfaces. This provides a low friction device which makes it easier to open and close the door, as well as reducing wear of the bearing blocks and gear hinge cutout edges. The end edges of the bearing blocks are preferably helically shaped. In addition, the gear segment portions may have ends which are shaped and sized to mate with the end edges of the bearings. Such a configuration results in a self-closing door.
A device such as a spring plunger may be used to hold the door open a desired amount so a person can easily see if a bathroom stall is occupied. The force of the spring in the spring plunger can easily be overcome to close the stall door.
Other advantages, objects and/or purposes of the invention will be apparent to persons familiar with constructions of this general type upon reading the following specification and inspecting the accompanying drawings.